Develop Reference

Store values from dynamically generated text boxes into array

I'm creating a Time table generating website as a part of my project and I am stuck at one point.
Using for loop, I am generating user selected text boxes for subjects and faculties. Now the problem is that I cannot get the values of those dynamically generated text boxes. I want to get the values and store it into array so that I can then later on store it to database
If I am using localstorage, then it sometimes shows NaN or undefined. Please help me out.
Following is my Jquery code
$.fn.CreateDynamicTextBoxes = function()
{
$('#DynamicTextBoxContainer, #DynamicTextBoxContainer2').css('display','block');
InputtedValue = $('#SemesterSubjectsSelection').val();
SubjectsNames = [];
for (i = 0; i < InputtedValue; i++)
{
TextBoxContainer1 = $('#DynamicTextBoxContainer');
TextBoxContainer2 = $('#DynamicTextBoxContainer2');
$('<input type="text" class="InputBoxes" id="SubjectTextBoxes'+i+'" placeholder="Subject '+i+' Name" style="margin:5px;" value=""><br>').appendTo(TextBoxContainer1);
$('<input type="text" class="InputBoxes" id="FacultyTextBoxes'+i+'" placeholder="Subject '+i+' Faculty Name" style="margin:5px;" value=""><br>').appendTo(TextBoxContainer2);
SubjectsNames['SubjectTextBoxes'+i];
}
$('#DynamicTextBoxContainer, #UnusedContainer, #DynamicTextBoxContainer2').css('border-top','1px solid #DDD');
}
$.fn.CreateTimeTable = function()
{
for (x = 0; x < i; x++)
{
localStorage.setItem("Main"+x, +SubjectsNames[i]);
}
}
I am also posting screenshot for better understanding

I understand you create 2 text boxes for each subject, one for subject, and second one for faculty. And you want it as a jQuery plugin.
First of all, I think you should create single plugin instead of two, and expose what you need from the plugin.
You should avoid global variables, right now you have InputtedValue, i, SubjectsNames, etc. declared as a global variables, and I believe you should not do that, but keep these variables inside you plugin and expose only what you really need.
You declare your SubjectNames, but later in first for loop you try to access its properties, and actually do nothing with this. In second for loop you try to access it as an array, but it's empty, as you did not assign any values in it.
Take a look at the snippet I created. I do not play much with jQuery, and especially with custom plugins, so the code is not perfect and can be optimized, but I believe it shows the idea. I pass some selectors as in configuration object to make it more reusable. I added 2 buttons to make it more "playable", but you can change it as you prefer. Prepare button creates your dynamic text boxes, and button Generate takes their values and "print" them in result div. generate method is exposed from the plugin to take the values outside the plugin, so you can do it whatever you want with them (e.g. store them in local storage).
$(function() {
$.fn.timeTables = function(config) {
// prepare variables with jQuery objects, based on selectors provided in config object
var numberOfSubjectsTextBox = $(config.numberOfSubjects);
var subjectsDiv = $(config.subjects);
var facultiesDiv = $(config.faculties);
var prepareButton = $(config.prepareButton);
var numberOfSubjects = 0;
prepareButton.click(function() {
// read number of subjects from the textbox - some validation should be added here
numberOfSubjects = +numberOfSubjectsTextBox.val();
// clear subjects and faculties div from any text boxes there
subjectsDiv.empty();
facultiesDiv.empty();
// create new text boxes for each subject and append them to proper div
// TODO: these inputs could be stored in arrays and used later
for (var i = 0; i < numberOfSubjects; i++) {
$('<input type="text" placeholder="Subject ' + i + '" />').appendTo(subjectsDiv);
$('<input type="text" placeholder="Faculty ' + i + '" />').appendTo(facultiesDiv);
}
});
function generate() {
// prepare result array
var result = [];
// get all text boxes from subjects and faculties divs
var subjectTextBoxes = subjectsDiv.find('input');
var facultiesTextBoxes = facultiesDiv.find('input');
// read subject and faculty for each subject - numberOfSubjects variable stores proper value
for (var i = 0; i < numberOfSubjects; i++) {
result.push({
subject: $(subjectTextBoxes[i]).val(),
faculty: $(facultiesTextBoxes[i]).val()
});
}
return result;
}
// expose generate function outside the plugin
return {
generate: generate
};
};
var tt = $('#container').timeTables({
numberOfSubjects: '#numberOfSubjects',
subjects: '#subjects',
faculties: '#faculties',
prepareButton: '#prepare'
});
$('#generate').click(function() {
// generate result and 'print' it to result div
var times = tt.generate();
var result = $('#result');
result.empty();
for (var i = 0; i < times.length; i++) {
$('<div>' + times[i].subject + ': ' + times[i].faculty + '</div>').appendTo(result);
}
});
});
#content div {
float: left;
}
#content div input {
display: block;
}
#footer {
clear: both;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="container">
<div id="header">
<input type="text" id="numberOfSubjects" placeholder="Number of subjects" />
<button id="prepare">
Prepare
</button>
</div>
<div id="content">
<div id="subjects">
</div>
<div id="faculties">
</div>
</div>
</div>
<div id="footer">
<button id="generate">Generate</button>
<div id="result">
</div>
</div>

Passing array -- scope

I want to pass an array from one external .js file to another.
Each of these files works fine by themselves, but I am having a problem passing the array from pickClass.js to displayStudent.js, and getting the names and "remaining" value to display in the html file. I know it has something to do with how the arrays are declared, but I can't seem to get it to work properly.
The first file declares the array choice:
(masterStudentList.js):
var class1 = ['Brown, Abe','Drifter, Charlie','Freed, Eve'];
var class2 = ['Vole, Ug','Xylo, William','Zyzzyx, Yakob'];
The second picks which array to use based on the radio buttons (pickClass.js):
var classPicked = array(1);
function randomize(){
return (Math.round(Math.random())-0.5); }
function radioResult(){
var chooseClass = document.getElementsByName("chooseClass");
for (i = 0; i < chooseClass.length; i++){currentButton = chooseClass[i];
if (currentButton.checked){
var selectedButton = currentButton.value;
} // end if
} // end for
var output = document.getElementById("output");
var response = "You chose ";
response += selectedButton + "\n";
output.innerHTML = response;
chosenClass = new Array();
if (selectedButton == "class1")
{chosenClass = class1;}
else
{chosenClass = class2;}
var text = "";
var nametext = "";
var i;
for (i = 0; i < chosenClass.length; i++) {
text += chosenClass[i]+ ' / ';
}
var showText = "";
l = chosenClass.length;
classPicked = Array(l);
for (var i = 0; i < l; ++i) {
classPicked[i] = chosenClass[i].split(', ').reverse().join(' ');
showText += classPicked[i]+ '<br>';
}
//return = classPicked;
document.getElementById("classList").innerHTML = classPicked;
} // end function
This works properly.
I then want to pass "classPicked" to another .js file (displayStudent.js) which will randomize the student list, loop and display the students for a few seconds, and then end with one student name.
basket = classPicked; //This is where the array should be passed
function randOrd(){
return (Math.round(Math.random())-0.5); }
function showBasket(){
mixedBasket = basket.sort( randOrd ); //randomize the array
var i = 0; // the index of the current item to show
document.getElementById("remaining").innerHTML = basket.length;
fruitDisplay = setInterval(function() {
document.getElementById('showStud')
.innerHTML = mixedBasket[i++]; // get the item and increment
if (i == mixedBasket.length) i = 0; // reset to first element if you've reached the end
}, 100); //speed to display items
var endFruitDisplay = setTimeout(function()
{ clearInterval(fruitDisplay);
var index = mixedBasket.indexOf(document.getElementById('showStud').innerHTML);
mixedBasket.splice(index,1);
}, 3500); //stop display after x milliseconds
}
Here is the html (master.html). It's just rough -- I'll be working on the layout later:
<html>
<head>
<script src="masterStudentList.js" type="text/javascript"></script>
<script src="pickClass.js" type="text/javascript"></script>
<script src="displayStudent.js" type="text/javascript"></script>
</head>
<body>
<h2>Choose Class</h2>
<form action = "">
<fieldset>
<input type = "radio"
name = "chooseClass"
id = "radSpoon"
value = "class1"
checked = "checked" />
<label for = "radSpoon">Class 1</label>
<input type = "radio"
name = "chooseClass"
id = "radFlower"
value = "class2" />
<label for = "radFlower">Class 2</label>
<button type = "button"
onclick = "radioResult()"> Choose Class
</button>
<div id = "output">
</fieldset>
</form>
</div>
<center>
<h1> <span id="chooseStud"></span><p></h1>
<script> var fruitSound = new Audio();
fruitSound.src = "boardfill.mp3";
function showFruitwithSound()
{
fruitSound.play(); // Play button sound now
showBasket()
}
</script>
Remaining: <span id = "remaining" ></span>
<p>
<button onclick="showFruitwithSound()">Choose Student</button>
</center>
pickedClassList = <p id = classList> </p>
</body>
</html>

You shouldn't use global variable like this (I encourage you to read more on this theme) and I'm not sure I understand what you're trying to do... but the solution of your issue should be to move the basket = classPicked; line into your showBasket method :
basket = classPicked; //This is where the array should be passed
function randOrd(){
return (Math.round(Math.random())-0.5);
}
function showBasket(){
// whatever
}
should be :
function randOrd(){
return (Math.round(Math.random())-0.5);
}
function showBasket(){
basket = classPicked; //This is where the array should be passed
// whatever
}
This way, each time you call showBasket, this method will use the last value of classPicked.
Otherwise, basket will always keep the reference on the first value of classPicked.
Why ? because each time you assign a new Array to the basket variable (classPicked = Array(l);) instead of changing directly it's content by :
emptying it : while (classPicked.length > 0) { classPicked.pop(); }
and then adding new data : classPicked.concat(chosenClass)

You can't pass things to files; you could call a function defined in displayStudent.js, pass it classPicked, and have it assign it to basket.

I noticed this at the end of your second chunk of code ...
} // end function
This could indicate the classPicked is declared inside a function (I don't see one on the code). Because it is inside function scope, your set of code that is trying to use it cannot.
Push the declaraction of classPicked outside of the function.
var classPicked = Array(1);
function thisusesclasspicked() {
...
Also, please start indenting your code properly, it will become much easier to maintain and read.
UPDATE FROM COMMENTS:
I see the declaration now ...
classPicked = Array(l);
for (var i = 0; i < l; ++i) {
classPicked[i] = chosenClass[i].split(', ').reverse().join(' ');
showText += classPicked[i]+ '<br>';
}
... however, you are re-assigning the array with an element of one just before you attempt to make modifications to it ... You are emptying it there: classPicked = Array(l);

Input entry is not catched in Javascript

I tried to build an application in which , there is one HTML page from which I get single input entry by using Submit button, and stores in the container(data structure) and dynamically show that list i.e., list of strings, on the same page
means whenever I click submit button, that entry will automatically
append on the existing list on the same page.
But in this task, firstly I try to catch that input in javascript file, and I am failing in the same. Can you tell me for this, which command will I use ?
Till now my work is :-
HTML FILE :-
<html>
<head>
<script type = "text/javascript" src = "operation_q_2.js"></script>
</head>
<body>
Enter String : <input type= "text" name = "name" id = "name_id"/>
<button type="button" onClick = "addString(this.input)">Submit</button>
</body>
</html>
JAVASCRIPT FILE:-
function addString(x) {
var val = x.name.value;
//var s = document.getElementById("name_id").getElementValue;//x.name.value;
alert(val);
}
EDITED
My New JAVASCRIPT FILE IS :-
var input = [];
function addString(x) {
var s = document.getElementById("name_id").value;//x.name.value;
input.push(input);
var size = input.length;
//alert(size);
printArray(size);
}
function printArray(size){
var div = document.createElement('div');
for (var i = 0 ; i < size; ++i) {
div.innerHTML += input[i] + "<br />";
}
document.body.appendChild(div);
//alert(size);
}
Here it stores the strings in the string, but unable to show on the web page.

See this fiddle: http://jsfiddle.net/MjyRt/
Javascript was almost right
function addString(x) {
var s = document.getElementById("name_id").value;//x.name.value;
alert(s);
}

Try to use jQuery (simpler)
function addString() {
var s = $('#name_id').val();//value of input;
$('#list').append(s+"<br/>");//list with entries
}
<div id='list'>
</div>

storing user input in array

I need to do the following (I'm a beginner in programming so please excuse me for my ignorance): I have to ask the user for three different pieces of information on three different text boxes on a form. Then the user has a button called "enter"and when he clicks on it the texts he entered on the three fields should be stored on three different arrays, at this stage I also want to see the user's input to check data is actually being stored in the array. I have beem trying unsuccessfully to get the application to store or show the data on just one of the arrays. I have 2 files: film.html and functions.js. Here's the code. Any help will be greatly appreciated!
<html>
<head>
<title>Film info</title>
<script src="jQuery.js" type="text/javascript"></script>
<script src="functions.js" type="text/javascript"></script>
</head>
<body>
<div id="form">
<h1><b>Please enter data</b></h1>
<hr size="3"/>
<br>
<label for="title">Title</label> <input id="title" type="text" >
<br>
<label for="name">Actor</label><input id="name" type="text">
<br>
<label for="tickets">tickets</label><input id="tickets" type="text">
<br>
<br>
<input type="button" value="Save" onclick="insert(this.form.title.value)">
<input type="button" value="Show data" onclick="show()"> <br>
<h2><b>Data:</b></h2>
<hr>
</div>
<div id= "display">
</div>
</body>
</html>
var title=new Array();
var name=new Array();
var tickets=new Array();
function insert(val){
title[title.length]=val;
}
function show() {
var string="<b>All Elements of the Array :</b><br>";
for(i = 0; i < title.length; i++) {
string =string+title[i]+"<br>";
}
if(title.length > 0)
document.getElementById('myDiv').innerHTML = string;
}

You're not actually going out after the values. You would need to gather them like this:
var title = document.getElementById("title").value;
var name = document.getElementById("name").value;
var tickets = document.getElementById("tickets").value;
You could put all of these in one array:
var myArray = [ title, name, tickets ];
Or many arrays:
var titleArr = [ title ];
var nameArr = [ name ];
var ticketsArr = [ tickets ];
Or, if the arrays already exist, you can use their .push() method to push new values onto it:
var titleArr = [];
function addTitle ( title ) {
titleArr.push( title );
console.log( "Titles: " + titleArr.join(", ") );
}
Your save button doesn't work because you refer to this.form, however you don't have a form on the page. In order for this to work you would need to have <form> tags wrapping your fields:
I've made several corrections, and placed the changes on jsbin: http://jsbin.com/ufanep/2/edit
The new form follows:
<form>
<h1>Please enter data</h1>
<input id="title" type="text" />
<input id="name" type="text" />
<input id="tickets" type="text" />
<input type="button" value="Save" onclick="insert()" />
<input type="button" value="Show data" onclick="show()" />
</form>
<div id="display"></div>
There is still some room for improvement, such as removing the onclick attributes (those bindings should be done via JavaScript, but that's beyond the scope of this question).
I've also made some changes to your JavaScript. I start by creating three empty arrays:
var titles = [];
var names = [];
var tickets = [];
Now that we have these, we'll need references to our input fields.
var titleInput = document.getElementById("title");
var nameInput = document.getElementById("name");
var ticketInput = document.getElementById("tickets");
I'm also getting a reference to our message display box.
var messageBox = document.getElementById("display");
The insert() function uses the references to each input field to get their value. It then uses the push() method on the respective arrays to put the current value into the array.
Once it's done, it cals the clearAndShow() function which is responsible for clearing these fields (making them ready for the next round of input), and showing the combined results of the three arrays.
function insert ( ) {
titles.push( titleInput.value );
names.push( nameInput.value );
tickets.push( ticketInput.value );
clearAndShow();
}
This function, as previously stated, starts by setting the .value property of each input to an empty string. It then clears out the .innerHTML of our message box. Lastly, it calls the join() method on all of our arrays to convert their values into a comma-separated list of values. This resulting string is then passed into the message box.
function clearAndShow () {
titleInput.value = "";
nameInput.value = "";
ticketInput.value = "";
messageBox.innerHTML = "";
messageBox.innerHTML += "Titles: " + titles.join(", ") + "<br/>";
messageBox.innerHTML += "Names: " + names.join(", ") + "<br/>";
messageBox.innerHTML += "Tickets: " + tickets.join(", ");
}
The final result can be used online at http://jsbin.com/ufanep/2/edit

You have at least these 3 issues:
you are not getting the element's value properly
The div that you are trying to use to display whether the values have been saved or not has id display yet in your javascript you attempt to get element myDiv which is not even defined in your markup.
Never name variables with reserved keywords in javascript. using "string" as a variable name is NOT a good thing to do on most of the languages I can think of. I renamed your string variable to "content" instead. See below.
You can save all three values at once by doing:
var title=new Array();
var names=new Array();//renamed to names -added an S-
//to avoid conflicts with the input named "name"
var tickets=new Array();
function insert(){
var titleValue = document.getElementById('title').value;
var actorValue = document.getElementById('name').value;
var ticketsValue = document.getElementById('tickets').value;
title[title.length]=titleValue;
names[names.length]=actorValue;
tickets[tickets.length]=ticketsValue;
}
And then change the show function to:
function show() {
var content="<b>All Elements of the Arrays :</b><br>";
for(var i = 0; i < title.length; i++) {
content +=title[i]+"<br>";
}
for(var i = 0; i < names.length; i++) {
content +=names[i]+"<br>";
}
for(var i = 0; i < tickets.length; i++) {
content +=tickets[i]+"<br>";
}
document.getElementById('display').innerHTML = content; //note that I changed
//to 'display' because that's
//what you have in your markup
}
Here's a jsfiddle for you to play around.

How to get child element by ID in JavaScript?

I have following html:
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
How can I get textarea element? I can't use document.getElementById("textid") for it
I'm doing it like this now:
var note = document.getElementById("note");
var notetext = note.querySelector('#textid');
but it doesn't work in IE(8)
How else I can do it? jQuery is ok
Thanks

If jQuery is okay, you can use find(). It's basically equivalent to the way you are doing it right now.
$('#note').find('#textid');
You can also use jQuery selectors to basically achieve the same thing:
$('#note #textid');
Using these methods to get something that already has an ID is kind of strange, but I'm supplying these assuming it's not really how you plan on using it.
On a side note, you should know ID's should be unique in your webpage. If you plan on having multiple elements with the same "ID" consider using a specific class name.
Update 2020.03.10
It's a breeze to use native JS for this:
document.querySelector('#note #textid');
If you want to first find #note then #textid you have to check the first querySelector result. If it fails to match, chaining is no longer possible :(
var parent = document.querySelector('#note');
var child = parent ? parent.querySelector('#textid') : null;

Here is a pure JavaScript solution (without jQuery)
var _Utils = function ()
{
this.findChildById = function (element, childID, isSearchInnerDescendant) // isSearchInnerDescendant <= true for search in inner childern
{
var retElement = null;
var lstChildren = isSearchInnerDescendant ? Utils.getAllDescendant(element) : element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].id == childID)
{
retElement = lstChildren[i];
break;
}
}
return retElement;
}
this.getAllDescendant = function (element, lstChildrenNodes)
{
lstChildrenNodes = lstChildrenNodes ? lstChildrenNodes : [];
var lstChildren = element.childNodes;
for (var i = 0; i < lstChildren.length; i++)
{
if (lstChildren[i].nodeType == 1) // 1 is 'ELEMENT_NODE'
{
lstChildrenNodes.push(lstChildren[i]);
lstChildrenNodes = Utils.getAllDescendant(lstChildren[i], lstChildrenNodes);
}
}
return lstChildrenNodes;
}
}
var Utils = new _Utils;
Example of use:
var myDiv = document.createElement("div");
myDiv.innerHTML = "<table id='tableToolbar'>" +
"<tr>" +
"<td>" +
"<div id='divIdToSearch'>" +
"</div>" +
"</td>" +
"</tr>" +
"</table>";
var divToSearch = Utils.findChildById(myDiv, "divIdToSearch", true);

(Dwell in atom)
<div id="note">
<textarea id="textid" class="textclass">Text</textarea>
</div>
<script type="text/javascript">
var note = document.getElementById('textid').value;
alert(note);
</script>

Using jQuery
$('#note textarea');
or just
$('#textid');

$(selectedDOM).find();
function looking for all dom objects inside the selected DOM.
i.e.
<div id="mainDiv">
<p>Paragraph 1</p>
<p>Paragraph 2</p>
<div id="innerDiv">
link
<p>Paragraph 3</p>
</div>
</div>
here if you write;
$("#mainDiv").find("p");
you will get tree p elements together. On the other side,
$("#mainDiv").children("p");
Function searching in the just children DOMs of the selected DOM object. So, by this code you will get just paragraph 1 and paragraph 2. It is so beneficial to prevent browser doing unnecessary progress.